CCC and REXA to modernise stream turbine controls

REXA, the industry leader in Electraulic™ Technology, and Compressor Controls Corporation (CCC), a leading supplier of turbomachinery control solutions, announce a joint initiative to modernise steam turbine controls for enhanced performance based upon each company’s core competency.

With more than 10 000 turbomachinery trains worldwide powered by CCC control solutions, the company has deep expertise on how customers can achieve reliable, efficient plant operation. By upgrading mechanical and hydraulic governors to the latest technology in digital speed control, plant operators are able to achieve greater speed control and eliminate nuisance trips.

“Electronic speed control improves the precision of turbine speed control which results in smoother process control,” stated Emily Hoop, Marketing Manager of CCC. “Modernising turbomachinery with digital control requires retrofitting the steam turbine with a new steam valve actuator and adding speed sensors to measure the turbine shaft speed. The electronic overspeed strip system increases turbine safety by reliably shutting down the turbine should an overspeed event occur.”

For its part, REXA has decades of experience solving challenging industrial process control issues where other actuation technologies are unable to match the performance, accuracy, and reliability of the company’s electraulic technology. REXA’s patented “flow match valve” is used in conjunction with a bi-directional gear pump, in a self-contained, positive pressure, sealed hydraulic system. The actuator design completely eliminates the need for an HPU, hydraulic reservoir, and servo/proportional valves, removing the need for filtration and any oil based maintenance. It also lends itself to minimal oil requirements, typically requiring less than 2% of the oil of a comparable HPU-based hydraulic system.

“Steam turbine operators have relied upon our electraulic actuators for their rugged, responsive, and repeatable solution for turbine governor applications,” stated Mike Murphy, Rotating Equipment Industry Manager for REXA. “The combination of CCC’s state-of-the-art governor controls and REXA actuation will enable turbine engineers to operate their trains with tighter set points, improving overall efficiency, and increasing process uptime. Precise control of turbine speed has a host of benefits for process owners, who now will have the ability for effective load sharing and automatic start-up sequencing capability that is offered by a CCC controls upgrade. Routine maintenance cycles can be extended to 6 - 7 years with REXA technology, and elimination of control oil at the turbine deck can even lead to reduced insurance rates for the end user due to de-rating the risk of a fire.”

Once upgraded with CCC’s speed control and the REXA actuator, plant operators will find that the turbine can easily be controlled within a few rpm range. The final result is smoother process control, increased throughput, and less chance of process upsets.